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<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style>
#a1{width:710px; height:200px; background-color:#3F9; float:left; margin-bottom:10px;}
#a2{width:200px; height:200px; background-color:#C9C;float:left; margin-right:10px; margin-bottom:10px;}
#a3{width:500px; height:200px; background-color:#F06;float:left; margin-bottom:10px;}
#a4{width:710px; height:200px; background-color:#F06;float:left; margin-bottom:10px;}
#b1{width:710px; height:1100px; text-align:center;}
</style>
<body>
<div id="b1">
<div id="a1">我的</div>
<div id="a2">我的</div>
<div id="a3">我的</div>
<div id="a4">我的</div>




</body>

</html>
